Radio communication devices are increasingly being used to communicate in multiple RF bands. An example of a multiple band RF device is a device that is able to communicate by using either the 802.11(b) or the 802.11(a) standard. The 802.11(b) standard uses RF signals in the region near 2.4 GHz and the 802.11(a) standard uses RF signals that cover a broader frequency range in the region near 5.0 GHz. It is often desirable, especially in small and/or portable devices, to minimize the number of antennas that are used on the device, and using a single antenna to cover multiple bands generally provides savings in size and manufacturing cost. Antennas for portable electronics are typically mounted inside the devices' housing in order to physically protect the antenna structure.
RF antennas are generally required to be located physically near the RF circuits to which they connect. This physical location requirement, manufacturability considerations, and the fragility of many internal antenna structures, result in design decisions to mount antenna structures on the electronic devices' printed circuit boards. However, mounting the antenna on the circuit board occupies printed circuit board area and limits the size of the antenna structure in an effort to minimize printed circuit board size.
Therefore a need exists to overcome the problems with the prior art as discussed above.